Hi. I am 19 years old a get red places (sometimes circular, sometimes abnormally shaped, sometimes large, sometimes small) on my arms, backside of hands, forehead, stomach, chest. I ve tried to track what could be causing it, but it happens randomly, doesn t matter where I am or what I m doing. I can t feel them, and unless I see them I don t even know they are there. The come suddenly, and disappear quickly. Is this anything to worry about and what could it be?